The TC applies the brake of the offending wheel spinner, knocks down engine timing, and yanks the throttle back. It is VERY agressive.

It compares the difference of front wheel speed to rear wheel speed, making the assumption that the front wheels aren't gonna spin....

LT1 cars all had 8.5\" axles unless it came in a Limo, then it got the bullet proof 9.5 semi floater. (no, I don't recommend it as an upgrade, it is VERY heavy). Parts are common everywhere. I see them all over swapmeets, complete with 3.42 or 3.73 gears (used) that are half decent. But for carrier, look to Randy's ring and pinion, you can get a posi there, or Summit, or Jegs, and then you have to have it installed.

Do NOT look to get the PowerTrax unit or LockRight. They are quite dangerous, and should never be considered for on highway driving, they run locked all the time like a spool, and can cause very easy spinouts on slick roads (wet and icy/snowy). And they tend to fight you in slow gentle curves like highway turns, they want to fight you and stay locked up.

I would personally look at a Eaton posi (clutch posi, rebuildable), they are OEM type units for many. GM has also used Auburn (cone posi, not rebuildable). I like the Eaton design. They are solid and can be biased up to as high as 800# between the axles, stock GM is 300#, you can do 200# and 400# also.

In general the tighter the more it will fight you. My posi now is pretty tight, even in tight corners I have to give it more gas to keep the car moving, or goose it and light them up.... I like it!!!! I can really really get on it hard now where before I always had the feather the heck out of the one wheel wonder....

Given a choice, posi vs TC, posi wins by a LONG shot....

But swapping in a posi unit is not something the average backyard joe can do, it takes special tools (which aren't terribly expensive) and time and room and experience is really worth it. But don't be dicouraged, I am going to try it and maybe get my 3.42's setup with posi this weekend! We'll see how much time I have. I haven't done it, but plan for at least 8 hours to work.

Hi - so it's an 8.5\" axle. Don't they go way back to the late sixties?

I've got a 8.2\" in my Skylark with the 3.05 gears. I remember now that if I wanted an Eaton posi for the Skylark [which at the time was a favourite choice] it only came for 3.55 gears and up in the 8.2\" or for most gears in the 8.5\" - or somehting like that. Basically to go the easy route sticking with my gears in my axle I had to use an Auburn unit. It's not rebuildable which actually isn't so bad since I can't see me trashing it and I later found out that is what the factory Skylark GS cars with the 401 motor came with - an 8.2\" axle, 3.05 gears and an Auburn posi.

So putting a posi in the '94 FWB would be about the same as doing one in a Chevelle/ Monte Carlo/ 2nd Gen Camaro/ Firebird or similar - fine! It would be good to see how your's goes. Good luck for the weekend!

regards

Yup, the 8.5 (and 8.6) is just a grown up 8.2.... The 8.6 is also known as the 8 5/8\". I believe 8.6\" parts fit in a 8.5\" case and vice versa. But a true 8.6\" case is beefier than a 8.5\".

Your remarks on Lock-Rite are very interesting. I've had a Lock-Rite in my Ford Ranger for years and drive on ice covered roads for six months out of the year. In my experience it is about the least invasive LSR I have ever encountered. It doesn't click nearly as loud as a Detroit locker but it can get grabby and make bad noises on sharp turns in slush. The best Posi I ever had was a factory unit in a 1960 Chev El Camino. With one tire on glare ice and the other on pavement you could do burnouts on the pavement. Next best was a 1966 El Camino that sometimes required a pull on the handbrake to set it. The worst was a Mazda RX-7 Turbo which was almost like a completely open rear end. I tore it down to find out why and found the factory had installed the discs upside down but it didn't make any difference when I corrected it. For the most part, if a posi is really effective it makes the car drive like you're on the trolly tracks.

I still haven't figured out the diff (pun intended) in the Lock Rite to PowerTrax, but they seem to be nearly identical. I have read lots of people complaining about them when on slick surfaces with low traction causing many issues with spinning out, even driving very very careful. If it is a 4x4 Ranger then that is probably why you did ok, but a 2WD with both back tires LOCKED on ice would be quite dangerous. Even a really tight posi (like the 800# springs) would be pretty dangerous as well.

A snow packed road is probably relatively ok, but icy roads are a nightmare just about anytime. I have had my times on ice and don't relish it. Snow packed roads? Love em! I rather enjoy lots of snow. I hate the mess the salt does to them.....

Almost got stationed at a radar unit in the Army north of Fairbanks. Sorta wish I did, but I had a newborn and they changed my orders for Colorado Springs, CO....

Yes, I am the nut who thinks my 80 Trans AM is a good snow car, posi, V8 Turbo power and good tires and it was a ball!! Now I go for my 94 Fleetwood, but the ultimate is my 99 K2500 454 Burb.... G80 locker and all....

<br><br>Post edited by: Capture_you, at: 2007/07/24 13:33